• British Pharmacopoeia Volume V
  • Appendices

Appendix XI D. Foreign Matter

(Ph. Eur. method 2.8.2)

Herbal drugs should be free from moulds, insects and other animal contamination.

Foreign matter is material consisting of any or all of the following:

1) Foreign organs: matter coming from the source plant but not defined as the drug,

2) Foreign elements: matter not coming from the source plant and either of vegetable or mineral origin.

Determination of Foreign Matter

Weigh 100 g to 500 g of the substance to be examined, or the minimum quantity prescribed in the monograph, and spread it out in a thin layer. Examine for foreign matter by inspection with the unaided eye or by use of a lens (6 ×). Separate foreign matter and weigh it and calculate the percentage present.